The present invention relates to an apparatus and associated method for housing a circuit and, more particularly, to an apparatus and associated method for shielding a circuit from electromagnetic interference.
Electronic circuitry is used in a wide variety of applications, such as controlling the deployment of air bags in a occupant protection system. An electronic circuit is often formed or mounted upon a circuit board. The operation of electronic circuitry can be adversely affected by electromagnetic interference. Shielding electronic circuitry from electromagnetic interference can, therefore, improve the operation of the circuit.
The amount of electromagnetic interference to which electronic components are exposed can be limited by locating the components in a protective housing which shields the components from the interference. U.S. Pat. No. 5,872,332 discloses a molded housing with EMI shield. A metal shield is stamped from sheet metal into a box shape. The stamped metal box shields the circuit from electromagnetic interference. The metal box is then insert molded into a plastic housing. A circuit board containing necessary components is then placed within and secured to the housing.
U.S. Pat. No. 5,774,344 discloses a metallized plastic RFI/EMI shield for a circuit card. The shield is formed of a box enclosure with two casing halves.
The present invention is directed to a housing and associated method for shielding a circuit from electromagnetic interference.
In accordance with one exemplary embodiment of the invention, a housing for shielding a circuit from electromagnetic interference comprises at least one electrically conductive connector pin having a central portion, a first end portion and a second end portion. The housing also comprises an insulator. The central portion of the one connector pin is disposed within the insulator. The first end portion and the second end portion of the one connector pin extend outward from the insulator. A housing body is made from an electrically conductive moldable plastic material. The housing body is molded over at least a portion of the insulator to secure the insulator and thereby the connector pin in the housing.
In accordance with another exemplary embodiment of the invention, a method of making a housing for shielding a circuit from electromagnetic interference includes the steps of providing at least one electrically conductive connector pin for connection with the circuit in the housing; providing an electrically non-conductive insulator; securing the connector pin in the insulator to form a sub-assembly; providing a mold for forming the housing; placing the subassembly at least partially in the mold; providing an electrically conductive moldable plastic material; and molding the plastic material in the mold to form the housing. The molding step includes molding the plastic material over at least a portion of the insulator to secure the insulator and thereby the connector pin to the housing.